Structure and Magnetic Properties of Hard Magnetic Nanocrystalline Oxide-Based Alloys

Abstract

The structure and properties of SrFe12O19 powders, which were produced by mechanical activation followed by annealing and had a nanocrystalline structure, were studied. The powders prepared exhibit a high coercive force μ0Hci=0.40-0.45 Т. The substantially higher coercive force (up to 0.75-0.82 T) was typical to SrFe12O19 powders produced by oxide-glass crystallization. Nanostructured materials comprising Fe3O4 and Fe phases with crystallite sizes of 10-30 nm are shown can be prepared from Fe2O3+Fe, Fe2O3+Fe+Co and FeO+Co powder mixtures by mechanochemical technique followed by annealing. These nanomaterials have the hard magnetic properties and their coercive force reaches μ0Hci 0. 08 T.